Relationship between epithelial to mesenchymal transition and chemoresistance of lung cancer

Objective： The aim of this study was to explore the correlation between epithelial to mesenchymal transition （EMT） and chemoresistance of non-small-cell lung cancer （NSCLC）. Methods： In vitro, the drug resistance index of cisplatin resistant lung adenocarcinoma cell line （A549/DDP） was detected by CCK-8 assay; the morphological change between A549/ DDP cells and lung adenocarcinoma cells （A549） was observed by phase contrast microscope; expression of EMT markers （including E-cadherin and vimentin） and resistance protein, excision repair cross-complementing 1 （ERCC1） was detected by immunocytochemistry. The expression of E-cadherin, vimentin and ERCC1 was investigated by immunohistochemistry in 120 cases of NSCLC, half of that were treated with pre-operative neoadjuvant chemotherapy （neoadjuvant chemotherapy group）, and the other underwent surgery alone （simple surgery group）. Results： There was a significant difference between the ICso （half maximal inhibitory concentration） of A549/DDP cells （5.20） and A549 cells （1.88） （P 〈 0.05）, and the drug resistance index of A549/DDP cells was 2.77. Compared with A549 cells, A549/DDP cells increased expression of ERCC1 （P 〈 0.05）. Moreover, A549/DDP cells showed morphological and phenotypic changes consistent with EMT： with spindle-shaped morphology, and decreased expression of E-cadherin and increased expression of vimentin. Immunohistochemistry showed significant positive correlation between the expression of ERCCI and vimentin （r = 0.496, 0.332, P 〈 0.05）, and significant negative correlation between the ERCCI and E-cadherin （r = -0.403, -0.295, P 〈 0.05） in neoadjuvant chemotherapy group and simple surgery group. In addition, compared with simple surgery group, the expression of ERCC1 （P = 0.003） and vimentin （P = 0.004） was significantly increased, and the expression of E-cadherin was decreased in neoadjuvant chemotherapy group （P = 0.032）. Cenclusion： A549/DDP cells acquired cisplatin-resistance and occurred EMT simultaneously; the phenomenon of chemoresistance and EMT was caused more easily in neoadjuvant chemotherapy group. As such, we further confirmed the close correlation between chemoresistance and EMT of NSCLC, and provided theoretical basis for the targeting therapy with EMT regulatory factor for chemoresistant NSCLC patients.     

耐药相关蛋白P-gp、MRP、LRP在非小细胞肺癌组织中的表达及意义

Objective： To explore the expression and significance of the multidrug resistance-related proteins P-glycoprotein （P-gp）, multidrug resistance-related protein （MRP）, lung resistance protein （LRP）in human non-small cell lung cancer （NSCLC） tissues and paratumor tissues. Methods： Immunohistochemistry （IHC） was used to examine the expression level of proteins P-gp, MRP and LRP in 43 samples of NSCLC and 15 samples of paratumor tissues. Results： The expression rates of P-gp, MRP and LRP in 43 tumor tissues were 74.42% （32/43）, 67.44% （29/43） and 88.37% （38/43）, respectively, while in 15 paratumor tissues were 13.33% （2/15）, 20.00% （3/15） and 6.67% （1/15）, respectively. There was significant difference in the expression of proteins （P-gp, MRP and LRP） between lung cancer tissues and paratumor tissues （P 〈 0.05）. The expression of proteins P-gp, LRP in lung adenocarcinoma were higher than that in other pathological carcinomas （P 〈 0.05）. The expression of protein MRP was not related to pathological type, clinical stage and classification of histodifferentiation （P 〉 0.05）. Conclusion： Multidrug resistance is more common in NSCLC. The proteins of P-gp, MRP and LRP participated in the formation of multidrug resistance in lung cancer. Detection of multidrug resistance-related proteins in lung cancer tissues may be useful to choice drugs.     

Effects of Prd×4 protein expression changes on the proliferation,apoptosis and migration of human lung adenocarcinoma A549 cells北大核心CSCD

Objective: To investigate the effects of up-regulating or silencing peroxiredoxin 4 (Prd×4) protein expression on the proliferation, apoptosis and migration of human lung adenocarcinoma A549 cells. Methods: The recombinant plasmid pcDNA3.0-HA-Prd×4 and specific siRNA targeting human Prdx 4 gene (Prd×4-siRNA) were transfected into A549 cells by liposome, respectively; while the empty vector pcDNA3.0-HA and the negative control-siRNA were used as the controls. The expression levels of Prd×4 mRNA and protein were detected by real-time fluorescent quantitative-PCR and Western blotting, respectively. The proliferation and apoptosis of A549 cells were detected by CCK-8 assay and immunofluorescence assay, respectively. The migration ability of A549 cells was detected by wound-healing test and Transwell chamber assay. Results: The expression levels of Prd×4 mRNA and protein were up-regulated in A549 cells transfected with the recombinant plasmid pcDNA3.0-HA-Prd×4 (both P < 0.05), while they were down-regulated in A549 cells transfected with Prd×4-siRNA (both P < 0.01). The proliferation ability (D 450 nm) of A549 cells with Prd×4 over-expression was higher than that in the control group at 24, 48 and 72 h (all P < 0.05), and the difference at 96 h was most obvious (P < 0.01). The D 450 nm values of A549 cells with Prdx 4 gene-silencing were decreased (all P < 0.01) as compared with the control group at 24, 48, 72 and 96 h. After treatment with cisplatin for 24 and 48 h, the number of apoptotic cells in Prd×4 over-expression group was significantly decreased as compared with the control group (P < 0.05 and P < 0.01), while it was significantly increased in Prdx 4 gene-silencing group as compared with the control group (P < 0.05 and P < 0.01). The wound healing rate in Prd×4 over-expression group was higher than that in the control group (P < 0.01), while it was lower in Prdx 4 gene-silencing group than that in the control group (P < 0.01). The number of A549 cells passing through the membrane of Transwell chamber in Prd×4 over-expression group was significantly more than that in the control group (P < 0.01), while it was less in Prdx 4 genesilencing group than that in the control group (P < 0.01). Conclusion: Prd×4 can promote the proliferation and migration, while it can inhibit the apoptosis of A549 cells. Prd×4 may be a potential target for the clinical treatment of lung adenocarcinoma. Copyright © 2017 by TUMOR All rights reserved.     

转染外源CC10对肺腺癌细胞系A549的CyclinD1蛋白及mRNA的影响

Objective： To investigate the effects of exogenous CC10 gene transfection on cell cycle and the expression of cyclinD1 protein and mRNA in A549 cells. Methods： A549 cells in all test groups （group A to E） and control group （group F） were transfected with exogenous CC10 gene by liposome for 8, 16, 24, 36, 48 and 0 h respectively. CC10 protein expression was detected in A549 cells by Western blot. The growth inhibitory rate was detected by MTT method. Flow cyometry analysis （FCS） and AnnexinV-PI staining were used to determine the changes of cell cycle progression and apoptosis rate in all groups. CyclinD1 protein and mRNA expression in A549 cells was detected by the methods of immunocytochemistry and RT-PCR. Results： Exogenous CC10 gene could inhibit the growth of A549 cells, and the growth inhibitory rates in all test groups （from group A to E） were 24.7%, 33.1%, 44.3%, 61.7% and 74.2% respectively, and that in group F was 6.24%. CC10 blocked the cell cycle progression at G0/G1 and induced apoptosis gradually. In A549 cells of test groups, the expression of cyclinD1 protein and mRNA was significantly decreased. Conclusion： The inhibitory effects of the transfection of exogenous CC10 gene on G0/G1 cycle of lung cancer cells might be related with the down-regulation of cyclinD1 gene.     

Inhibition of proliferation of human breast cancer MCF-7 cells by small interference RNA against LRP16 gene

Objective: Our previous studies have firstly demonstrated that 17β-E2 up-regulates LRP16 gene expression in human breast cancer MCF-7 cells, and ectopic expression of the LRP16 gene promotes MCF-7 cells proliferation. Here, the effects of the LRP16 gene expression on growth of MCF-7 human breast cancer cells and the mechanism were further studied by establishing two stably LRP16-inhibitory MCR-7 cell lines. Methods: Hairpin small interference RNA (siRNA)strategy, bY which hairpin siRNA was released by U6 promoter and was mediated by pLPC-based retroviralvector, was adopted to knockdown endogenous LRP16 level in MCF-7 cells. And the hairpin siRNA against green fluorescence protein (GFP) was used as the negative control. The suppressant efficiency of the LRP16 gene expression was confirmed by Nothern blot.Cell proliferation assay and soft agar colony formation assay were used to determine the status of the cell sproliferation. Cell cycle checkpoints including cyclin E and cyclin D1 were examined by Western blot. Results:The results from cell proliferation assays suggested that down-regulation of LRP16 gene expression is capable of inhibiting MCF-7 breast cancer cell growth and down-regulation of the LRP16 gene expression is able to inhibit anchorage-independent growth of breast cancer cells in soft agar. We also demonstrated that cyclin E and cyclin D1 proteins were much lower in the LRP16-inhibitory cells than in the control cells.Conclusion: These data suggest that LRP16 gene play an important role in MCF-7 cells proliferation by regulating the pathway of the G1/S transition and may function as an important modulator in regulating the process of tumorigenesis in human breast.     

Pin1、β-连接素和细胞周期素D1在老年肺癌组织中的表达及临床意义

Objective:To investigate the expressions and correlations of Pin1,β-catenin and cyclin D1 in elderly lung carcinomas.Methods:The expressions of Pin1,β-catenin and cyclin D1 were examined in the specimens of 92 elderly lung carcinomas and 10 normal lung tissues by immunohistochemistry and explored the relationship between the expression levels and clinicopathological factors.Results:(1) The overexpression of Pin1 and cyclin D1 in lung carcinomas was 46 (50%)cases and 60 (65.22%) cases respectively and 56 (60.82%) cases showed positive immunoreactivity for β-catenin in the nuclear and (or) cytoplasmic fraction in tumor tissues,In normal tissue,the expressions of Pin1 and cyclin D1 were negative,the expression of β-catenin was lied in cell membrane.(2) In lung carcinomas the expressions of Pin1,β-catenin and cyclin D1 correlated with tumor differentiation (P＜0.05).The pesitive expression rate and intensity of Pin1 correlated with tumor stage (P=0.032) and lymph node positive disease (P=0.041).The expression of β-catenin correlated with lymph node positive disease (P=0.012).(3) High expression levels of Pin1 correlated with aberrant β-catenin expression (P=0.000) but did not show a correlation with cyclin D1 (P=0.157).Conclusion:In elderly lung carcinomas,the positive expression of Pin1 causes abnormal accumulation of β-catenin and actives its target gene,however,this target gene was not cyclin DI.The detection of Pin1 expression had some clinical significance in estimating prognosis of elderly patient with lung carcinomas.     

Transfection of the Human Sodium/Iodide Symporter （NIS） Gene with Liposomes and the Expression of the NIS Protein in Human Lung A549 Cancer Cells

OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided into an experimental group transfected with a recombinant pcDNA3-hNIS plasmid and a control group transfected only with a pcDNA3 plasmid. The recombinant plasmid vector encoding the hNIS gene （pcDNA3-hNIS） was amplified, purified and identified. The hNIS gene was followed by DNA sequencing. A Western blot and an immunohistochemical assay were applied to detect the hNIS protein expression in the transfected human lung A549 cancer cells. RESULTS Restriction enzyme digestion and DNA sequencing results showed the size and direction of the inserted gene in the recombinant pcD- NA3-hNIS plasmid was correct. The Western blot method and immunohistochemical analysis showed a positive NIS protein expression in the experimental group. The NIS protein was detected mainly in the cell membranes showing a positive rate up to 70.6% with no expression of the NIS protein in the control group. There was a significant difference between two groups （P=0.000）. CONCLUSION The hNIS gene was transfected effectively into human lung A549 cancer cells mediated by Lipofectamine 2000, and was expressed with its protein in vitro.     

Role of toll-like receptor 4-dependent signaling pathway in lipopolysaccharide-induced human lung carcinoma cell proliferation北大核心

Objective: Our aim was to study the mechanism through which toll-like receptor 4 (TLR4) -dependent signaling pathway was involved in lipopolysaccharide (LPS) -induced the proliferation of human lung adenocarcinoma A549 cells. Methods: MTT assay and flow cytometry (FCM) were performed to examine the proliferation of A549 cells after stimulation with LPS. Immunocytochemistry staining was used to evaluate the TLR4, c-Jun, c-Fos and nuclear factor-kappa B (NF-κB) protein expressions in A549 cells after treatment with different concentrations of LPS. Results: LPS stimulated the proliferation of A549 cells, especially after 24 h treatment. The ratio of cells in G2/M phase in the 100 ng/mL LPS group was significantly higher than that in 10 ng/mL LPS group. The difference was significant (P<0.05). The expressions of TLR4, c-Jun, c-Fos, and NF-κB detected in A549 cells were gradually elevated with the increase in the concentrations of LPS. The expressions of TLR4, c-Jun, c-Fos and NF-κB were the highest in LPS (100 ng/mL) group compared with the control group (P <0.05). Conclusion: LPS promoted the proliferation of A549 cells. The mechanism may be explained as follows: binding with TLR4 receptor, stimulating TLR4 signaling pathways, and then activating AP-1 (heterodimer of c-Jun and c-Fos) and NF-κB , finally inducing persisted proliferation of human lung carcinoma cells.     

Experimental Study of Ultrasound on MDR in a Human Tumor in Vivo

OBJECTIVE To evaluate the potential efficacy of low-intensity ultrasound(US)in combination with anticancer drugs to reverse multidrug resistance(MDR)in nude mice. METHODS A total of 40 male and female athymic nude mice were inoculated subcutaneously with 5x106 HepG 2 /ADM and HepG 2 cells.Ultrasound with pulsed irradiation at an average intensity of 0.5 W/cm2 was given to the tumor area 10 min after administration of adriamycin(ADM).The tumor 3 dimensional diameters were measured by calipers before and after treatment, and the tumor growth indexes(TGI)calculated.RT-PCR was used to detect the gene levels of the HepG 2 /ADM cells.Immunohistochemical analyses for MDR proteins were conducted on the tumor tissues. RESULTS The ultrasonic treatment resulted in an average reduction in the tumor volume of 62%one month later.The relative mRNA levels of MDR1 and MRP were significantly different among the folowing 4 groups: untreated group as control,ADM treated;US treated;and ADM plus US treated.The mRNA levels of mdr1 and mrp were down-regulated in the US groups compared to those of the non-ultrasound groups by multiple com- parisons.The relative mRNA levels of lrp expression were not significantly changed.The results of immunohistochemistry indicated that tumor tissue from animals treated with US had remarkably low mdr1 and mrp expression. CONCLUSION The results showed that low-intensity US can effectively reduce the size of adriamycin-resistant human hepotacarcinoma in a nude mouse model,and support the efficacy of US to overcome multiple mechanisms of drug resistance.     

Influence of Tamoxifen or the combination of Tamoxifen and Cisplatin on the growth of human lung adenocarcinoma A549 cells

The experiment aims to investigate the influence of Tamoxifen and the combination of Tamoxifen and Cisplatin （DDP） on the growth of human lung adenocarcinoma A549 cells. Methods： We treated human lung adenocarcinoma A549 cells with different concentrations of Tamoxifen, DDP and combination of DDP and Tamoxifen with non-toxicity for 72 h. Then we calculated the inhibition rate through MTT approach and detected the apoptosis rate by flow cytometry. The statistical analysis was performed with SPSS 13.0 software and statistical differences were determined by one-way ANOVA. The data were expressed as the mean ＋ standard deviation and all experiments were performed in three times. The value of P 〈 0.05 was considered to indicate a statistically significant difference. Results： 1. The inhibition rates of Tamoxifen with 2.5 pmol/L, 5 tJmol/L, 10 μmol/L, and 20 μmol/L on the growth of the A549 cells were 18.7%, 25.8%, 54% and 98.8%, respectively （P = 0.000）. Tamoxifen with concentration of 1 μmol/L has no obvious cytoxicity on the A549 cells （P 〉 0.05）. 2. As the increase concentration of Tarnoxifen, the S stage and G2/M of the A549 cells decreased while the G0/G1 increased. The apoptosis rate of Tamoxifen with 0 μmol/L, 0.1 μmol/L, 1 μmol/L and 10 μmol/L on the A549 cells were 6.51%, 8.91%, 17.97% and 42.7%, respectively. 3. The inhibition rates of combination of Tamoxifen with 1 μmol/L and DDP with 1.25 μg/mL, 2.5 μg/mL, 5 μg/mL, 10 μg/mL and 20 μg/mL on the A549 cells were 40.4%, 54.4%, 72.9%, 86.1% and 92.4%, respectively （P 〈 0.05）. Conclusion： Tamoxifen can inhibit the proliferation of human lung adenocarcinoma A549 cells and induce the apoptosis of the A549 cells. The combination of Tamoxifen with non-toxicity and DDP can improve the sensitivity of chemotherapy on the A549 cells.     

Two-Dimensional （Polyacrylamide） Gel Electrophoresis Analysis of Apoptosis Induced by Harringtonine in K562 Cells

OBJECTIVE The anti-tumor drug, harringtonine (HT), has been extensively used with satisfactory results in the treatment of acute or chronic myeloid leukemia. Previous studies have shown that the anti-tumor activity of the drug is related to induced apoptosis of tumor cells, but the molecular mechanism still remains unclear. The main purpose of this research was to analyze the protein profiles formed during HT-induced apoptosis in K562 cells and to screen the apoptotic-related proteins.METHODS Annexin V and Pi double staining was used in combination with flow cytometry to examine the early and the late stages of HT-induced apoptosis in K562 cells. In addition two-dimensional gel electrophoresis and computer-assisted image analysis were employed to separate and compare the HT-induced apoptotic proteins of the K562 cells and the controls.RESULTS When a concentration of 10 μg/ml HT was used to treat K562 cells,the percentage of the early-apoptotic cells (Annexin V /PI-) was found to be 28.3% and 18.1% at 5 and 24 h, respectively (P＜0.01), while the rate of lateapoptotic cells (Annexin V /PI ) was at a level of 9.1% and 20.2%,respectively (P＜0.01). Matching analysis of the proteome among the control group and the early- and late-apoptotic groups showed 1,300 ± 50 protein spots which were identified in the control K562 cells with a matching rate of 88.3 ± 2.0 % for the protein spots in the two treated groups. Ten protein spots showed overt and steady changes in both quality and quantity in the cells of the late-apoptotic group (P＜0.01), among which the level of expression for eight of the ten protein spots was up-regulated after apoptosis, one was down-regulated and one was merely expressed as in the control cells.CONCLUSION The proteins with differential expression might be important proteins involved in the process of apoptosis in K562 cells induced by HT.     

Effects of HLEC on the secreted proteins of epithelial ovarian cancer cells prone to metastasize to lymph nodes

Objective： To study explores the effect of HLEC on the secreted proteins of epithelial ovarian cancer （EOC） cells （SKOV3-PM4） with directional highly lymphatic metastasis. Methods： Supernatants of four groups of cultured cells, namely, SKOV3 （A）, SKOV3＋HLEC （B）, SKOV3-PM4 （C）, SKOV3-PM4＋HLEC （D）, were collected, and their proteins were detected by antibody arrays and iTRAOcZD-LC-MALDI- TOF/TOF/MS. Significantly differential proteins were further analyzed via bioinformatics and validated in human serums and cell media via ELISA. Results： Results of antibody arrays and mass spectrometry demonstrated that GRN and VEGFA were upregulated in group C （compared with group A）, whereas IGFBP7 and SPARC were downregulated in group D （compared with group C）. Comprehensive bioinformatics analysis results showed that IGFBP7 and VEGFA were closely linked to each other. Further validation with serums showed statistical significance in VEGFA and IGFBP7 levels among groups of patients with ovarian cancers, benign tumors, and control groups. Two proteins were upegulated in the first group. VEGFA in the control group was downregulated. For IGFBP, upregulation in the control group and down-regulation in the first group were also observed. Conclusion： The HLEC microenvironment is closely associated with directional metastasis to lymph nodes and with differential proteins including cell stromal proteins and adhesion factors. The upregulation of VEGFA and GRN and the downregulation of SPARC and IGFBP7 are closely associated with directional metastasis to lymph nodes in EOC cells.     

SREBP2m promotes proliferation and migration of hepatocarcinoma cells and inhibits apoptosis through cholesterol metabolism damage北大核心CSCD

Objective: To investigate the effects of sterol regulatory element binding protein 2 (SREBP2) on the metabolism of cholesterol as well as the proliferation, apoptosis and migration of normal liver LO2 cells and hepatocellular carcinoma HepG2 cells. Methods: By using pAd-Easy-1 adenovirus vector system, the recombinant adenovirus Ad-SREBP2m (carrying the splicing form of SREBP2) and Ad-GFP (as the control) were constructed, and then infected into LO2 and HepG2 cells, respectively. The total cholesterol level in LO2 and HepG2 cells after infection was detected by a cholesterol quantification kit. The expression levels of SREBP2m, cholesterol synthesis rate-limiting enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) and apoptosis-related proteins (including caspase 3, cleaved-caspase 3 and caspase 12) were detected by Western blotting. The effects of Ad-SREBP2m overexpression on the proliferation, cell cycle, apoptosis and migration of LO2 or HepG2 cells were detected by EdU staining method, FCM and scratch wound healing test, respectively. Results: The recombinant adenovirus Ad-SREBP2m was successfully constructed. Compared with the Ad-GFP group, the expression levels of SREBP2m and its target protein HMGCR were up-regulated (both P < 0.05), and the total cholesterol level increased significantly in LO2 cells and HepG2 cells infected with Ad-SREBP2m (both P < 0.05). In LO2 cells infected with Ad-SREBP2m, the proportion of G1-, S- and G2-phase cells was not significantly changed (all P > 0.05); while in HepG2 cells infected with Ad-SREBP2m, the proportion of G1-phase cells decreased significantly (P < 0.001), but the proportion of S-phase cells increased significantly (P < 0.001). SREBP2m overexpression promoted the proliferation of HepG2 cells (P < 0.001), but had no effect on the proliferation of LO2 cells. The expression levels of total caspase 3, cleaved-caspase 3 and caspase 12 were significantly higher in LO2 cells infected with Ad-SREBP2m than those in Ad-GFP group (all P < 0.001), while the expression levels of total caspase 3, cleaved-caspase 3 and caspase 12 were decreased in HepG2 cells infected with Ad-SREBP2m (all P < 0.05). The apoptosis rate of LO2 cells after Ad-SREBP2m infection was increased by (11.40±0.52)% (P < 0.001), while the apoptosis rate of HepG2 cells in Ad-SREBP2m group was decreased by (4.17±0.47)% as compared with Ad-GFP group (P < 0.05). The migration distance of HepG2 cells in Ad-SREBP2m group was (1.17±0.12) mm more than that in Ad-GFP group (P < 0.05). Conclusion: Overexpression of SREBP2m can promote the proliferation and migration and inhibit the apoptosis of hepatocellular carcinoma HepG2 cells, but it can promote apoptosis of normal liver LO2 cells. Copyright © 2018 by TUMOR. All rights reserved.     

Glycogen synthase kinase 3β inhibitor (2′Z,3′E)-6-bromo-indirubin-3′-oxime enhances drug resistance to 5-fluorouracil chemotherapy in colon cancer cells

Objective: To explore the effects and mechanism of glycogen synthase kinase 3β (GSK-3β) inhibitor (2’Z,3’E)-6-bromo-indirubin-3’-oxime (BIO) on drug resistance in colon cancer cells. Methods: The colon cancer SW480 and SW620 cells were treated with BIO, 5-fluorouracil (5-FU) and BIO/5‐FU, separately. Cell cycle distribution, apoptosis level and efflux ability of rhodamine 123 (Rh123) were detected by flow cytometry. The protein expressions of P-glycoprotein (P-gp), multidrug resistance protein 2 (MRP2), thymidylate synthase (TS), β-catenin, E2F-1 and Bcl-2 were detected by Western blot. β-catenin and P-gp were stained with double immunofluorescence and observed under a confocal microscope. Results: BIO up-regulated β-catenin, P-gp, MRP2 and TS, enhanced the efflux ability of Rh123, decreased Bcl-2 protein and gave the opposite effect to E2F-1 protein in SW480 and SW620 cells. Furthermore, BIO significantly inhibited cell apoptosis, increased S and G 2 /M phase cells, and reduced the cell apoptosis induced by 5-FU in SW480 cells, whereas the effects were slight or not obvious in SW620 cells. Conclusion: GSK-3β was involved in drug resistance regulation, and activation of β-catenin and inhibition of E2F-1 may be the most responsible for the enhancement of 5-FU chemotherapy resistance induced by GSK-3β inhibitor BIO in colon cancer.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.